Tamper-proof connector



B. s. SAUTER TAMPER-PROOF CONNECTOR Filed OOE. 14,

Fe 15, T936 INVENTOR.

BOBBIE S. SAUTER VIE ATTORNEYS United States Patent 3,234,842 TAMPER-PROOF CONNECTOR Bobbie S. Sauter, Van Nuys, Califi, assignor to Deutsch Fastener Corp., Los Angeles, Calif. Filed Oct. 14, 1963, Ser. No. 316,068 Claims. (Ql. 85-34) This invention pertains to a fastener adapted to resist cutting or abrading of the shank.

One area of use of the device of this invention is in connecting coin return boxes to pay telephones, although the invention is not restricted to such purpose. Telephone ,coin return boxes, of course, are mounted about a transverse shaft at the lower portion of a pay telephone. Whencoins are returned, they drop into a receptacle portion of the coin return box, which then is pivoted outwardly about the shaft to permit removal of the coins. This type of construction has led to a great deal of theft from paytelephones. The thieves will slip a hack saw blade in the two vertical slots between the coin return receptacle and the body of the telephone. The pin then is sawn through, and the ,coin return box is removed. Then cotton will be stuffed into the coin chute of the telephone, and the coin return box replaced in its opening. After an interval of time the thief will return, again removing the coin return box and taking the cotton from the coin chute of the telephone. This allows him to collect all the coins that have accumulated during the intervening period. The result has been a severe financial loss for telephone companies and individuals using the pay telephones.

The present invention provides a fastener which can be used as the means to secure the coin return box to the telephone body, and includes a shank that cannot be severed or abradedin the manner described above. This is accomplished by providing freely rotatable sleeves in annular recesses in the shank of the fastener. These sleeves are located at the areas of the graps between the coin return box and the telephone body. Consequently, when the hack saw blade is applied to the rotatable sleeves, it will merely turn the sleeves but will not saw the material of the sleeves. The invention is provided with an expansible end and a drive pin so that it is a blind fastener and can be used for field replacement of existing coin return box pins. In a modified version of the invention a hard material, such as porcelain, is applied to the area of the fastener where the cutting or abrasion may occur to provide a surface that will be harder than the material of a saw blade and, hence for all practical purposes, prevent the severing of the shank of the fastener.

It is an object of this invention to provide a fastener which normallycannot be severed or abraded.

Another object of this invention is to provide a means for preventing theft from telephone coin boxes.

A further object of this invention is to provide a tamper-proof connector of the blind type that is usable for field replacement.

An additional object of this invention is to provide a tamper-proof connector of relatively simple and low cost construction.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is' a side elevational view of the device of this invention as installed in a telephone;

FIGURE 2 is a side elevational view, partially in section, of the sleeve portion of the fastener;

FIGURE 3 is an end elevational view of the sleeve, illustrating the cross slots to permit expansion by the drive pin;

H 3,234,842 Patented Feb. 15, 1966 FIGURE 4 is a side elevational view of the pin that is driven into the sleeve;

FIGURE 5 is a perspective view of one of the rotatable collars fitting on the shank of the sleeve;

FIGURE 6 is a fragmentary sectional view, illustrating the drive pin as initially inserted into the sleeve;

FIGURE 7 is a fragmentary sectional view similar to FIGURE 6, showing the drive pin as fully inserted;

FIGURE 8 is a fragmentary sectional view of the end of the sleeve, illustrating the manner in which the drive pin provides an upset head; and

FIGURE 9 is a fragmentary elevational view, partially in section, of a modified form of this invention in which a hard material is utilized on the shank to, resist the cutting or abrading.

With reference to .the drawings, the device of this invention is in the form of an elongated slim fastener 10, illustrated inFIGURE 1 as used in connection with a pay telephone 11. The telephone includes a body portion 12 whichpivotally carries a coin return box 13. The latter member is rotatable about the axis of the fastener 10, and defines a receptacle to receive coins that are to be returned by the pay telephone. There will be a narrow gap 14 on either side of the coin return box 13 between the coin return box and the body 12 of the telephone 11. This gap is needed to assure free rotation of the coin return box and easy access to its contents.

The fastener 10 of this invention includes an elongated sleeve 15, illustrated in detail in FIGURE 2. One end of the sleeve 15 includes a head 16, which may be adapted for countersunk installations and hence present a frustoconical under surface. The head is hollow, having a central recess 17. An elongated shank 18 extends from the head 16 of the sleeve and at its outer end 19 .is provided with longitudinally inwardly extending slots 20. These slots may be of simple cruciform pattern, as seen in FIGURE 3, readily cut intothe end of the sleeve by two passes of a saw blade. An annular groove 21 inwardly of .the end 19 provides a space for the run out of the tool used in slotting the end of the fastener and also provides a reduced area in the sleeve to enable the rivet to be upset by smaller driving loads.

The interior surface 22 of the sleeve 15 is of constant cylindrical diameter, but at the end portion 19 presents a frustoconicalinwardly convergent surface 23 leading to an outer portion 24 of smaller diameter.

The sleeve 15 is adapted to receivea drive pin 26, shown separated fromthe remainder of the fastener in FIGURE 4. The drive pin includes an elongated. shank 27 complementary to the interiordiameter portion 22 of the sleeve. The shank 27 terminates in a conical end 28. Head 29 is at the opposite end of the shank 27. The head is dome-shaped, giving it. a hollow under portion 30. Intermediate .the ends ,of the sleeve 15 are two portions 32 and 33,0f reduced exterior diameter. Each of these is adapted to receive a rotatable collar 35. The collars 35 are of split construction, each having a longitudinally extending gap 36, as seen in FIGURE 5. This allows the collars 35 to be expanded or formed over the exterior of the sleeve and to be contracted into the annular areas 32 and 33 of reduced diameter. The thickness of the wall of the collar 35 is selected so that, when in place, the collars do not project outwardly beyond the exterior surface of the shank 18 of the sleeve 15. The collars are shorter than the spaces 32 and 33, and of greater internal diameter than the sleeve at those locations, so that the collars are freely rotatable relative to the shank 18 of the sleeve 15.

In use of the device of this invention, the sleeve 15 is inserted through the opening devised to receive it, such as the apertures through the body 12 and the coin return box 13 of a pay telephone. It is constructued so that the spaces 32 and 33, and hence the collars 35, thereby are positioned in alignment with the slots 14 at the side edges of the coin return box, as best seen in FIGURE 1. Generally, prior to installation, the drive pin 26 will be located within the opening 22 of the sleeve. Then when the fastener is in place, the drive pin 26 is driven axially inwardly of the sleeve, first bringing it to the position of FIGURE 6 where the head 29 is received Within the opening 17 in the head 16 of the sleeve. Additional inward driving force forces the hollow head 29 of the drive pin all the way into the recess, as indicated in FIGURE 7. The domed outer portion of the head is expanded in the radial direction by this movement of the drive pin, which locks the head 29 in the recess 17. Thus, the drive pin will not move outwardly of the sleeve once it has been driven into place.

As this movement of the drive pin occurs, the opposite end 28 of the driven pin reacts against the frustoconical surface 23 of the sleeve. This expands the end 19 of the sleeve, as indicated in FIGURE 8. The conical end 28 acts as a cam surface, or Wedge, that easily expands the end portion 19, providing an upset head on the blind side that prevents movement of the fastener out of the opening receiving it. The cross slots 20 and the annular groove 21 facilitate this expansion of the end 19 of the sleeve.

When the fastener is installed in this manner, it will be found that it cannot be severed by the access provided through the gaps 14. A hack saw blade placed on the collars 35 will do nothing more than rotate the collars on the shank 18 of the sleeve 15. Because of the fact that the collars 35 turn freely on the sleeve, the hack saw cannot cut the collars or the shank of the fastener. Hence, by the installation of the fastener 10 of this invention, theft from pay telephones is prevented. The collars 35 do not project beyond the circumferential surface of of the sleeve, and hence will not tend to bind upon the surface of the opening in which they are received. Moreover, the provision of the expansible end portion 19 on the sleeve 15 permits the fastener to be installed in existing telephones without requiring removal of the telephone or dismantling of any of its components.

As an alternative to the above-described design, the fastener can be constructed generally as shown in FIG- URE 9. Here, instead of rotatable collars, the shank of the fastener is provided at appropriate locations with annular sections of a particularly hard material which will resist cutting from a saw or other device. Hence, as shown in FIGURE 9, the shank 37 of the sleeve of the fastener may include a section 38 of reduced diameter, which may be somewhat similar to the portions 32 and 33. Within this area is deposited a quantity 39 of a hard material, such as porcelain, glass or the like. It may be baked, if desired, to provide the customary hard surface of such materials. The ring 39 of hard material will prevent sawing by being harder than the teeth of the saw which is used in attempting to sever it. The fact that it is difficult to bear pressure against the pin when the fastener is intalled in a telephone coin return box adds to the difficulty of cutting the ring 39 even with determined efforts over a period of time.

Various modifications of the invention are possible, depending upon the particular use intended for it. For example, there need not be two of the collars 35 on the shank of the fastener, but instead one, three or other numbers may be included as needed.

The foregoing detailed description is to be clearly understood as given by way of iliustration and example only, the spirit and scope of this invention being limited solely by the appended claims.

I claim:

1. A tamper-proof connector comprising a sleeve,

a head at one end of said sleeve,

said sleeve having inwardly directed inner surface portions at the opposite end portion thereof,

said sleeve having at least one annular recessed area in the exterior surface thereof,

a pin receivable in said sleeve,

said pin having an abutment surface engageable with said inwardly directed surface of said sleeve for causing expansion of said opposite end of said sleeve upon axial movement of said pin inwardly of said sleeve,

and a collar received in said annular recessed area,

said collar being freely rotatable relative to said sleeve for precluding cutting of said sleeve by a cutting tool. 2. A device as recited in claim 1 in which said collar is longitudinally split for installation of said collar by contracting said collar into said recessed area. 3. A device as recited in claim 1 in which said sleeve is longitudinally split at said opposite end portion, for facilitating expansion of said opposite end portion upon said axial movement of said pin.

4. A device as recited in claim 1 in which said head includes a recess,

said pin having a head thereon, said head of said pin being receivable in said recess.

5. A device as recited in claim 4 in which said head of said pin is dome-shaped, presenting an outwardly convex surface, whereby upon the receipt of said head in said recess said head is bendable radially outward to lock said pin in said sleeve.

References Cited by the Examiner UNITED STATES PATENTS 90,219 5/1869 Baker 189-9 1,348,517 8/1920 Porter -8.6 1,904,180 3/1933 Wagner 74580 2,219,788 10/1940 Pleister 8585 2,575,213 11/1951 Fruth 8585 2,922,571 1/1960 Kennedy et al 232-57.5 3,116,013 12/1963 EHO et al. 23257.5

FRANK B. SHERRY, Primary Examiner, 

1. A TAMPER-PROOF CONNECTOR COMPRISING A SLEEVE, A HEAD AT ONE END OF SAID SLEEVE, SAID SLEEVE HAVING INWARDLY DIRECTED INNER SURFACE PORTIONS AT THE OPPOSITE END PORTION THEREOF, SAID SLEEVE HAVING AT LEAST ONE ANNULAR RECESSED AREA IN THE EXTERIOR SURFACE THEREOF, A PIN RECEIVABLE IN SAID SLEEVE, SAID PIN HAVING AN ABUTMENT SURFACE ENGAGEABLE WITH SAID INWARDLY DIRECTED SURFACE OF SAID SLEEVE FOR CAUSING EXPANSION OF SAID OPPOSITE END OF SAID SLEEVE UPON AXIAL MOVEMENT OF SAID PIN INWARDLY OF SAID SLEEVE, AND A COLLAR RECEIVED IN SAID ANNULAR RECESSED AREA, SAID COLLAR BEING FREELY ROTATABLE RELATIVE TO SAID SLEEVE FOR PRECLUDING CUTTING OF SAID SLEEVE BY A CUTTING TOOL. 